Yeah, I think in the future and even now to some extent we won't really need coin join. But lightning is not magic(for those reading this. Darth knows this very well). Part of this will be the increase in bitcoin usage driving up on-chain fees.

The other thing is that adoption grows most people will be paid in bitcoin not exchanging it for fiat. They will likely be paid off-chain via lightning.

I've said it before but thanks for your guides @DarthCoin.